The Foundation published an article about Net Neutrality. Their argument (stating they don't break the principle) is quite solid, and you used it in the past: Wikipedia is not a commercial service, it's common good. We can make a parallel about calling the police or the fire brigade being free of charge on telephone networks.

So what's your point? You fear Facebook et al. will invoke zero-rated Wikipedia as an argument to ask for the same, thus breaking net neutrality?